基于模糊综合评价法的栗水河水质评价与对比分析

Water Quality Evaluation of the Lishui River Based on Fuzzy Comprehensive Evaluation Method and Comparative Analysis

采用模糊综合评价法、单因子指数法和内梅罗指数法对上栗县栗水河进行了水质评价,并对评价结果进行对比分析。研究区水质时空特征为:确定了五日生化需氧量、溶解氧和总氮三个主要水质污染指标,超标率分别为66.7%,66.7%和33.3%;时间尺度上水质情况3月最好,9月次之,6月最差;空间尺度上水质情况未表现出明显差异性。三种方法的评价结果在总体趋势上与水质时空变化特征相符,不同评价方法的水质级别占比略有差别,其中模糊综合评价法评价结果优于单因子评价法和内梅罗指数法,较科学合理地判定了河流水质等级,更贴近实际水质状况。

Fuzzy comprehensive evaluation method,single factor index method and Nemerow index method were applied to evaluate the water quality of the Lishui river in Shangli County,and the evaluation results were compared and analyzed.Temporal and spatial characteristics of water quality in the study area are as follows:BOD_(5),DO and TN were identified as main water quality indexes with the exceeding standard rate of 66.7%,66.7%and 33.3%respectively.Water quality was best in March,following by September and worst in June over the time.There were no obvious spatial difference among different indexes on the spatial scale.The results of the three evaluation methods were consistent with temporal and spatial variation characteristics of water quality in the overall trend,but proportions of water quality grade of different evaluation methods were slightly different.The evaluation result of fuzzy comprehensive evaluation method,were better than the single factor index method and Nemerow index method,which classified river water quality grade scientifically and reasonably,and was closer to actual water quality.